14 files changed, 96 insertions, 1 deletions

diff --git a/src/diff.c b/src/diff.c
index d97dcd9d2..d98a28966 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -493,8 +493,10 @@ static int diff_list_apply_options(
 
 	/* Don't set GIT_DIFFCAPS_USE_DEV - compile time option in core git */
 
-	/* Set GIT_DIFFCAPS_TRUST_NANOSECS on a platform basis */
+	/* Don't trust nanoseconds; we do not load nanos from disk */
+#ifdef GIT_USE_NSEC
 	diff->diffcaps = diff->diffcaps | GIT_DIFFCAPS_TRUST_NANOSECS;
+#endif
 
 	/* If not given explicit `opts`, check `diff.xyz` configs */
 	if (!opts) {
diff --git a/tests/index/nsec.c b/tests/index/nsec.c
new file mode 100644
index 000000000..5004339f0
--- /dev/null
+++ b/tests/index/nsec.c
@@ -0,0 +1,78 @@
+#include "clar_libgit2.h"
+#include "index.h"
+#include "git2/sys/index.h"
+#include "git2/repository.h"
+#include "../reset/reset_helpers.h"
+
+static git_repository *repo;
+static git_index *repo_index;
+
+#define TEST_REPO_PATH "nsecs"
+
+// Fixture setup and teardown
+void test_index_nsec__initialize(void)
+{
+	repo = cl_git_sandbox_init("nsecs");
+	git_repository_index(&repo_index, repo);
+}
+
+void test_index_nsec__cleanup(void)
+{
+	git_index_free(repo_index);
+	repo_index = NULL;
+
+	cl_git_sandbox_cleanup();
+}
+
+static bool has_nsecs(void)
+{
+	const git_index_entry *entry;
+	size_t i;
+	bool has_nsecs = false;
+
+	for (i = 0; i < git_index_entrycount(repo_index); i++) {
+		entry = git_index_get_byindex(repo_index, i);
+
+		if (entry->ctime.nanoseconds || entry->mtime.nanoseconds) {
+			has_nsecs = true;
+			break;
+		}
+	}
+
+	return has_nsecs;
+}
+
+void test_index_nsec__has_nanos(void)
+{
+	cl_assert_equal_b(true, has_nsecs());
+}
+
+void test_index_nsec__staging_maintains_other_nanos(void)
+{
+	const git_index_entry *entry;
+
+	cl_git_rewritefile("nsecs/a.txt", "This is file A");
+	cl_git_pass(git_index_add_bypath(repo_index, "a.txt"));
+	cl_git_pass(git_index_write(repo_index));
+
+	cl_git_pass(git_index_write(repo_index));
+
+	git_index_read(repo_index, 1);
+	cl_assert_equal_b(true, has_nsecs());
+
+	cl_assert((entry = git_index_get_bypath(repo_index, "a.txt", 0)));
+	cl_assert_equal_i(0, entry->ctime.nanoseconds);
+	cl_assert_equal_i(0, entry->mtime.nanoseconds);
+}
+
+void test_index_nsec__status_doesnt_clear_nsecs(void)
+{
+	git_status_list *statuslist;
+
+	cl_git_pass(git_status_list_new(&statuslist, repo, NULL));
+
+	git_index_read(repo_index, 1);
+	cl_assert_equal_b(true, has_nsecs());
+
+	git_status_list_free(statuslist);
+}
diff --git a/tests/resources/nsecs/.gitted/HEAD b/tests/resources/nsecs/.gitted/HEAD
new file mode 100644
index 000000000..cb089cd89
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/HEAD
@@ -0,0 +1 @@
+ref: refs/heads/master
diff --git a/tests/resources/nsecs/.gitted/config b/tests/resources/nsecs/.gitted/config
new file mode 100644
index 000000000..78387c50b
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/config
@@ -0,0 +1,8 @@
+[core]
+	repositoryformatversion = 0
+	filemode = false
+	bare = false
+	logallrefupdates = true
+	symlinks = false
+	ignorecase = true
+	hideDotFiles = dotGitOnly
diff --git a/tests/resources/nsecs/.gitted/index b/tests/resources/nsecs/.gitted/index
new file mode 100644
index 000000000..9233f1b11
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/index
diff --git a/tests/resources/nsecs/.gitted/objects/03/1986a8372d1442cfe9e3b54906a9aadc524a7e b/tests/resources/nsecs/.gitted/objects/03/1986a8372d1442cfe9e3b54906a9aadc524a7e
new file mode 100644
index 000000000..a813b7424
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/objects/03/1986a8372d1442cfe9e3b54906a9aadc524a7e
@@ -0,0 +1,2 @@
+x
��A
+�0D]��J�4D��Mu-��/�"F�H��F��f�
�Paʠ�Z��r�n�X��*�4kU��i�xK-#%�y�	Z����2�0�;�Џ;���
Ű�J�Z7F����R�B�y�?g�?�<�^@�]f˔G�v��ܵ�N�
UOKv
\ No newline at end of file
diff --git a/tests/resources/nsecs/.gitted/objects/03/9afd91c98f82c14e425bb6796d8ca98e9c8cac b/tests/resources/nsecs/.gitted/objects/03/9afd91c98f82c14e425bb6796d8ca98e9c8cac
new file mode 100644
index 000000000..74bb7d3fe
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/objects/03/9afd91c98f82c14e425bb6796d8ca98e9c8cac
diff --git a/tests/resources/nsecs/.gitted/objects/6d/8b18077cc99abd8dda05a6062c646406abb2d4 b/tests/resources/nsecs/.gitted/objects/6d/8b18077cc99abd8dda05a6062c646406abb2d4
new file mode 100644
index 000000000..7bf3a956c
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/objects/6d/8b18077cc99abd8dda05a6062c646406abb2d4
diff --git a/tests/resources/nsecs/.gitted/objects/c5/12b6c64656b87ea8caf37a32bc5a562d797745 b/tests/resources/nsecs/.gitted/objects/c5/12b6c64656b87ea8caf37a32bc5a562d797745
new file mode 100644
index 000000000..dcf4c8ccb
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/objects/c5/12b6c64656b87ea8caf37a32bc5a562d797745
diff --git a/tests/resources/nsecs/.gitted/objects/df/78d3d51c369e1d2f1eadb73464aadd931d56b4 b/tests/resources/nsecs/.gitted/objects/df/78d3d51c369e1d2f1eadb73464aadd931d56b4
new file mode 100644
index 000000000..df45d3314
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/objects/df/78d3d51c369e1d2f1eadb73464aadd931d56b4
diff --git a/tests/resources/nsecs/.gitted/refs/heads/master b/tests/resources/nsecs/.gitted/refs/heads/master
new file mode 100644
index 000000000..3dda65b65
--- /dev/null
+++ b/tests/resources/nsecs/.gitted/refs/heads/master
@@ -0,0 +1 @@
+031986a8372d1442cfe9e3b54906a9aadc524a7e
diff --git a/tests/resources/nsecs/a.txt b/tests/resources/nsecs/a.txt
new file mode 100644
index 000000000..be4c1ee68
--- /dev/null
+++ b/tests/resources/nsecs/a.txt
@@ -0,0 +1 @@
+File A

diff --git a/tests/resources/nsecs/b.txt b/tests/resources/nsecs/b.txt
new file mode 100644
index 000000000..19a0af40f
--- /dev/null
+++ b/tests/resources/nsecs/b.txt
@@ -0,0 +1 @@
+File B

diff --git a/tests/resources/nsecs/c.txt b/tests/resources/nsecs/c.txt
new file mode 100644
index 000000000..31d776008
--- /dev/null
+++ b/tests/resources/nsecs/c.txt
@@ -0,0 +1 @@
+File C